Previous studies have shown that folate deficiency, increased homocysteine, impaired metylation have been identified in depressive disorder. Recently, growing research has resulted in the biological association between obsessive-compulsive disorder (OCD) and affective disorders. Therefore, in the present study it was evaluated whether or not folate and homocysteine levels changed. Serum folate and homocysteine concentrations were measured in 23 patients with OCD and in same number of controls. In addition, all patients were assessed by Yale-Brown Obsession Compulsion Scale (Y-BOCS). Serum folate values were significantly lower in OCD patients than in controls, while homocysteine concentrations were higher in patients compared with controls. Serum folate values were significantly and negatively related to Y-BOCS scores. Total serum homocysteine concentrations were positively correlated to Y-BOCS scores and the duration of illness. There was a trend toward a negative correlation between the concentrations of serum folate and homocysteine. In conclusion, we identified that a group of patients with OCD might have folate deficiency, higher homocysteine levels and probable impaired metylation and monoamine metabolism.

There is a large amount of convincing data demonstrating that reactive oxygen species (ROS) are involved in initiation and development of many different forms of neuropsychiatric disorders. The levels of oxidants and antioxidants in schizophrenia have been evaluated. However, measurements of total antioxidant response (TAR) were not evaluated up to now. Therefore, the objectives of this study are to investigate plasma TAR levels in schizophrenia subtypes. A total of 76 patients with schizophrenia and 25 healthy volunteers were included in the study. Positive and Negative Syndrome Scale (SANS and SAPS, respectively) were applied to patients. TAR values were determined in the plasma of normal healthy controls and patients with schizophrenia. Plasma TAR levels of each schizophrenia subtype were significantly lower than healthy controls (P < 0.01 for disorganized, residual and undifferentiated subtypes and P < 0.01 for paranoid subtype). When intragroup comparisons were performed, paranoid subtype had higher plasma TAR levels compared to other subtypes (P < 0.01). Accordingly, as a whole group, patients with schizophrenia had lower plasma TAR levels compared to controls. Plasma TAR levels were significantly and negatively correlated with SANS scores, and duration of illness was evaluated but not related to other parameters. Consequently, the present study further emphasizes the growing consideration that free radical damage may have an important etiopathogenetic role on the development of schizophrenia and suggests that decreased plasma total antioxidant levels may be related to the progression of illness.

It has been suggested that the extract of gingko biloba (EGb) may enhance the efficiency of the classic antipsychotic haloperidol in patients with chronic schizophrenia, especially on positive symptoms, and reduce serum superoxide dismutase (SOD) levels. Therefore, we decided to evaluate the therapeutic effect of EGb and to examine the effect of it on the levels of antioxidant enzymes in schizophrenic patients on olanzapine treatment. We hypothesized that EGb would have the beneficial effects on schizophrenic symptoms and might cause reductions in antioxidant enzymes. The subjects were randomly assigned to the two groups: olanzapine plus EGb (group I) ( n = 15) and olanzapine alone (group II) ( n = 14). The patients were evaluated at baseline and at week 8 with respect to the Positive and Negative Syndrome Scale (PANSS), serum SOD, catalase (CAT), and glutathion peroxidase (GPX) levels. At baseline, no statistically significant difference regarding the mean total PANSS scores between treatment groups was found. At the evaluation of week 8, a significant difference in mean Scale for the Assessment of Postive Symptoms (SAPS) scores but not in Scale for the Assessment of Negative Symptoms scores between groups was found. Total patients had statistically significant higher serum SOD, CAT and GPX levels compared to control groups at baseline. At 8 weeks, there were significant differences in the mean decrease in SOD and CAT levels but not in GPX levels between treatment groups. The changes in SOD and CAT levels were correlated with the change in SAPS in group I, but not in the group II . The present study supported the findings of the previous study demonstrating that EGb might enhance the efficiency of antipsychotic in patients with schizophrenia, particularly on positive symptoms of the disorder.